1) Field of the Invention
The present invention relates to a delivery device and to a delivery device for positioning and deploying an implantable device within a lumen.
2) Description of Related Art
Implantable medical devices are valuable tools of modern medicine. In general, an implantable device is a device or structure configured to be inserted or embedded into a patient for a variety of functions. Implantable devices include stents, filters, markers, drug delivery devices, valves, and monitors.
In particular, stents are implantable devices that are inserted into body lumina such as vessels or passages to keep the lumen open and prevent closure due to a stricture, external compression, or internal obstruction. Stents are commonly used to keep blood vessels open in the coronary arteries, and they are frequently inserted into the ureters to maintain drainage from the kidneys, the bile duct for pancreatic cancer or cholangiocarcinoma, or the esophagus or airways for strictures or cancer. Vascular as well as nonvascular stenting has evolved significantly; unfortunately, there remain significant limitations with respect to effectively implanting the stents into a patient's lumen.
In order to serve its desired function, the stent and most other implantable devices must be delivered precisely and oriented correctly. Improper installation can lead to several adverse complications including tissue luminal inflammation and tissue granulation. In order to facilitate the delivery of implantable devices, delivery devices, such as endoscopes and catheters, have been utilized to deploy implantable devices more precisely.
Delivery devices vary in shape and structure. However, in general, a delivery device includes a handle and one or more movable tubular members extending from the handle. The delivery device further includes a deployment mechanism for moving or operating the tubular members between positions. For example, International Publication Number WO 2005/070095 to Mangiardi et al., which is assigned to the assignee of the present application and is incorporated herein by reference, discloses a delivery device having a handle, a deployment mechanism, and an inner tubular member disposed within an outer tubular member. The outer tubular member is typically shorter than the inner tubular member and movable relative to the inner tubular member. A distal region of the outer tubular member surrounds the implantable device, such as a stent, and maintains the stent in a crimped delivery configuration, while a distal region of the inner tubular member is surrounded by the stent. Once properly positioned at a targeted site, the outer tubular member is retracted to deploy the stent and allow the stent to radially expand.
The effective release of the stent depends on the movement of the outer tubular member relative to the inner tubular member. Therefore, an impairment of the movement between the tubular members may adversely affect the accuracy of the stent release. Although the sources of such impairment may vary, one known source is the operator of the delivery device. More specifically, some operators have a tendency to grasp the outer tubular member during use of the delivery device, which may impair the movement between the tubular members. As another example, the tubular members may become pinched or otherwise interfered with due to the tortuous path that the delivery device may take within the patient's lumen or from the pressure of the walls of the patient's lumen.
In light of the foregoing, there is a need in the industry for a delivery device with enhanced protection for the tubular members.